A prototype "Smart Home" holds out a tantalising glimpse of the kind
of energy-saving gadgets, gizmos and materials we can expect to see inside
our homes in just a few years’ time.

Imagine a house that switches the lights off for you when the sun comes out; a house that will tell you, while you are at work, that your son has left his Xbox on, a house built with such smart materials that even the micro glass sphere-enriched paint on its walls has insulating properties.

This house actually exists – in prototype at least – on parkland beside the M1 just north of Watford. Currently being tested by scientists at the Building Research Establishment (BRE), it holds out a tantalising glimpse of the kind of energy-saving gadgets, gizmos and materials we can expect to see inside our homes in just a few years’ time.

I am visiting on a November day: clouds scud across a sky alternating alarmingly in colour between plum and azure. From the outside, the sweeping angled conservatory roof looks like conventional glass. From inside, each pane of glass now reveals that it has tiny wires embedded inside it and is part of a 5kw solar electricity (pv) system. These panes of glass, although transparent, are shaded orange, the optimal colour for tracking ultraviolet light. The colour is slightly disconcerting, as if a sodium street light were directly overhead.

“The development of eco materials is moving at such a rapid rate that we have moved from the conventional opaque, blue-coloured polycrystalline solar collectors that you see on roofs to these transparent orange-coloured panes of glass,” says John O’Brien of the BRE. “In about two years manufacturers will be able to make colourless glass collectors and then every office, and ultimately every home in the country, would, in theory, be able to generate its own electricity unobtrusively.”

Not only is the conservatory roof a giant solar electricity generator, but, acting as a buffer between the main living quarters of the house and the outside, it operates as a “solar space”. In winter its design captures warmth from the low-hanging sun and warms the air inside, protecting the rest of the house from the cold.

As with all solar panel systems, it is affected by seasonal variations, generating more than it needs in the summer, and less than it needs in the winter, an obvious weakness in the technology.

“The prevailing wisdom used to be that the only way to store excess electricity was in batteries,” says O’Brien. “This is both inefficient and cumbersome: you would need the battery the size of a submarine buried under the house to provide electricity to last the winter.” However, the BRE is currently working with partners on storing solar pv electricity as heat, which is converted back to electricity when needed.

“This is still a fair way off but one day will be achievable, and gets around the drawback of solar electricity, which is that in northern latitudes like our own, it doesn’t provide when it is most needed.”

Inside the house, motion and light sensors ensure the most efficient use of the low-energy lighting system and app-enabled “smart plugs” allow socket-by-socket monitoring of electricity use. When O’Brien tells me that not only can I check, remotely, whether my son has left his computer on, but that I can also remotely shut it down, a world of possibilities opens up. Forced to abandon his assault on ancient Carthage (his favourite computer game), he may actually pick up Virgil’s “Aeneid” and read about Dido’s passion for Aeneas.

The BRE Smart Home is a renovated house built in 1998. While the existing walls still perform well, the so-called “House of the Future” only scored an E on current Energy Performance ratings before the refurbishment this year. Now scoring an A/B rating the Smart Home demonstrates how much energy efficiency technologies have improved.

“Fifteen years ago this house was at the cutting edge of technology but a lot of the original materials and designs have become outdated,” says O’Brien. He points to the original rainwater harvesting system which has become obsolete. “The water was collected underground, the pumps failed and leaves clogged up the system,” he says. The refurbished house will use an under-the-eaves rainwater tank, a wide, shallow collector that distributes the weight of the water evenly inside the roof. “This means it will feed the toilets and appliances by gravity rather than needing a pump, which can go wrong.”

Futuristic materials including the glass-embedded paint and paraffin wax-embedded insulating panels which store heat in the day and release it at night are also being tested in the house. I have seen a glimpse of the future and it’s ripe with energy-saving opportunities – if a little orange at the moment.